“Challenge assumptions” is an ideation method that helps UX (user experience) design teams break free from conventional thinking and push past false beliefs. You use it to identify and question the assumptions your design decisions rest on, then flip or remove them to uncover fresh solutions. It’s a powerful way to spark innovation and shift how you see a problem.
In this video, William Hudson: User Experience Strategist and Founder of Syntagm Ltd., explains how design thinking helps you challenge assumptions to redefine problems and generate innovative solutions.
Consider where design would be if nobody had dared to push past the assumption that users “needed” physical keypads on handheld devices. Or, on a slightly different note, how about the famous story of the truck that became wedged under a bridge? In this well-known anecdote, the problem stumped experts who suggested complex solutions, until a child reportedly proposed simply letting air out of the tires. Whether or not the story is true, it illustrates how stepping outside assumptions can reveal simple, overlooked solutions. Sometimes it takes the distance of perspective to afford users (or trapped truck drivers) the freedom to move forward. A key part? Getting past assumptions and not-so-accurate grasps of reality that might otherwise hold you back.
The method, “challenge assumptions,” helps you find essential truths about what users really want. It can also show you how you can fly high above design conventions that seem “the only way to do it,” even if they revolve around incorrect viewpoints of what’s really going on. Assumptions about users, for example, can pose one of the most hazardous threats to effective design.
What makes assumptions so risky? They often lurk in plain sight, too close to a designer’s way of envisioning a situation (and the people in it) to stand out as potentially flawed beliefs. For example, consider the “more is better” assumption regarding features for an app. Power users may appreciate the extra control from an overdose of functionality, but most users won’t, feeling overwhelmed, and the app’s usability will suffer.
Not all assumptions are “bad”; it’s just that their validity needs testing rather than designers clinging to them with blind faith. When you use this structured ideation technique, it helps your team rethink the boundaries of a problem by questioning the beliefs and constraints you treat as givens. You list those assumptions, flip them with “what if” and “why” questions, and then use the results to spark original, disruptive ideas. Challenging assumptions works well in the ideation phase in design thinking and other user-centered processes because many of the constraints we follow aren’t real; they’re just habits of thought.
Take the following steps to weed out assumptions you and your team may have and challenge them head-on:
Gather your team and write down every assumption you’re making about the product, user, market, or technology. Think broadly about these questions:
“What do we assume users want or need?”
“What do we assume is technically required?”
“What do we assume about user behavior?”
“What rules are we following without questioning?”
Common assumptions include things like these: “The homepage must have a navigation bar,” or “Users won’t scroll beyond the fold.” These often sound like facts, but they’re not; they’re design habits. Although you may find some truth in assumptions (and convention may seem to “dictate” some design norms), it’s imperative to take nothing for granted, get them out in the open, and make them prove their validity.
Now go through the list and flip each assumption. Ask bold, brave, and provocative questions like:
“What if the opposite were true?”
“Why do we think this is required?”
“What would happen if we removed this entirely?”
“Could we do this in a completely different way?”
The goal isn’t just to poke holes, but to reframe the challenge. For example, if your assumption is “Users must log in to see their dashboard,” challenge it by asking: “What if users didn’t have to log in at all? What if the dashboard wasn’t the default starting point?” Some team members may express doubt at some questions (or even seem amazed at the “audacity” of asking them), but therein lies the strength of challenging assumptions (and the danger of not challenging them).
Once you’ve challenged several assumptions, use them as springboards for ideation. Each flipped assumption can become a new opportunity to reach a fresh design solution that might work wonders for users:
“What would a dashboard-less experience look like?”
“What if the interface adapted based on time of day?”
“What if users didn’t need to type anything to get started?”
Take these prompts and brainstorm freely so you can “run away” with them. Use sketching, storyboarding, or mind maps to explore the new space.
In this video, William Hudson shows you how to run judgment-free brainstorming, using quick sketches and mind maps to spark bold ideas.
From your ideas, choose a few that feel promising and feasible. Create quick prototypes (low-fidelity paper prototypes, for example) or sketch user flows. Then test these with users, or at least discuss them with cross-functional teams to see how viable they are.
In this video, Alan Dix, Author of the bestselling book “Human-Computer Interaction” and Director of the Computational Foundry at Swansea University, shows you how to turn promising ideas into quick prototypes, test them with users, and iterate toward a good-enough solution.
After the session, document what you learned. Which assumptions proved invalid? Which ones proved useful to question? Make a note of these so that your team can revisit them in future sessions.
As you start getting to grips with assumptions and proceed through the above steps:
Realize that some constraints are real for a reason. While outdated beliefs comprise many constraints, some all-too-real legal, regulatory, or safety requirements might limit your options. Be careful to distinguish the two; when in doubt, ask “Who says this has to be true?”
In this video, William Hudson explains how identifying true constraints early, including regulatory and technical requirements, helps you distinguish unavoidable limits from inherited assumptions so you can design within what is genuinely possible.
Make the most of team diversity for richer sessions. Hear from everyone, including development, product, support, and marketing people. Each function holds different assumptions about what’s possible or valuable, and each viewpoint might spot assumptions you mightn’t notice you have.
Timebox the exercise. Don’t let it drag; set timers for each phase, such as 15 minutes to list, 15 to challenge, and 20 to ideate.
Encourage “stupid” questions. Many breakthroughs come from asking what seems self-evident to everyone. That’s where the real assumptions lie, so take the initiative to push past the givens and be that “Advocate of the Obvious.” The team members who think “But everyone knows that’s a fact!” may soon become contributors who say, “Wow! I’d never thought of it like that! So, does that mean we might try something like…?”
Visualize everything. Use whiteboards, sticky notes, or virtual tools, since seeing the connections helps generate more ideas.
Follow up with action. Don’t let the ideas sit on a whiteboard. Convert a few into prototypes or user test concepts as soon as possible.
Use it regularly. This isn’t just for stuck teams, as a kind of medicine to aid mental constipation. Use it in kickoffs, retros, and midway checkpoints to keep your thinking sharp and your team members more aware.
When you systematically question assumptions in your design process, you unlock several key advantages, namely:
You stop circling familiar solutions and open the door to radically different concepts, ones that wouldn’t emerge under your original constraints.
You are not your users, as much as you might believe you’re fully aligned with how they see their world. And when you challenge what you think you know about users, you create space for more accurate, research-informed solutions. This often leads to designing experiences that users find more relevant, inclusive, and useful, and proves your empathy for them.
Explore how empathic design turns stressful airport moments into calm, inclusive experiences by prioritizing what users actually need, in this video.
By surfacing and testing assumptions early, you avoid sinking time and resources into products you and your team might build on shaky foundations. Many wrong ideas about user behavior, user needs, platform requirements, business rules, or technical feasibility have a nasty tendency to “hide” as you research or discuss insights with your team. If assumptions go unquestioned, they can limit the ideas a team is willing to consider. Worse, if an incorrect assumption makes it into the final design, it might spell disaster for the product.
The challenge assumptions technique encourages everyone, from designers to business stakeholders and beyond, to think more openly. It levels the playing field and fosters a more collaborative, creative culture, handy especially when cognitive biases can keep many team members from identifying and busting assumptions they might hold.
In this video, Alan Dix shows how biases like anchoring skew judgment and how changing the frame helps you challenge assumptions and break fixation.
When your team examines their thinking habits, they will become more self-aware and less attached to legacy decisions or outdated mental models. This creates a healthier design environment, one where you can spot and look past what might seem to be the one and only “truth.”
Perhaps most importantly, because this method reframes your problem space and gives you permission to question everything, it helps you turn mental roadblocks into launchpads for creativity.
The trick is to get the distance and insight to know when you’re stuck in familiar thought patterns or retreading over familiar design territory. More specifically, watch out for these symptoms of “assumptionitis”:
You feel stuck with familiar thought patterns or feel old solutions constraining you.
Your team keeps proposing the same features or flows.
The problem definition feels too narrow or “locked in.” For example, “How can we make our checkout button more noticeable so users complete their purchase?” might seem reasonable. However, what if the real problem is that users don’t trust the site or find the checkout process cumbersome?
You sense that your team is overlooking important user behaviors or needs.
You want to generate more unexpected, original ideas.
You suspect internal constraints (like time, budget, or technical requirements) are too easily accepted and your team has its “hands tied.”
It’s wise to use the challenging assumptions technique after early user research, too, when it’s time to frame how the product might take shape. Then, you’ll likely notice your team is already assuming things about how users should interact with the product or what’s feasible. That’s the perfect moment to slow down and challenge those beliefs, before they become deeply entrenched.
Overall, “challenge assumptions” isn’t just a clever ideation trick; it’s a mindset. It teaches teams to stay curious, question the status quo, and look past surface-level solutions. Even research-based insights can turn into assumptions if nobody tests them continuously. However, note that the goal isn’t to dismiss everything; it’s to examine beliefs critically and decide whether they still serve the project.
In UX design, where habits and heuristics often guide decision-making, “challenge assumptions” acts as a reset button. It forces you to ask: “What are we really designing for, and are we sure our starting point is even true?” Whole paradigms can change with the kind of creative push that empowers your next big idea to start where you certainty ends. In an ever-evolving arena where modern users want effective solutions to address real-world problems amid changing technology and new apps, don’t give assumptions a license to hijack true innovation. With courage, awareness, and insight, when you dare to inquire, you can reach heights where great ideas live and bring them down to street level standing on the solid ground of knowledge and valid insights.
For essential insights into assumptions and many other elements of effective design and ideation towards it, take our Design Thinking: The Ultimate Guide course.
Enjoy our Master Class Innovate with Design Thinking: Your Shortcut to Results with Amr Khalifeh, Senior Consultant at AJ&Smart.
Discover a wealth of insights on the method in our piece Learn How to Use the Challenge Assumptions Method.
Another effective method for challenging assumptions in design is through grounded theory research. Discover more in our article, Grounded Theory: Base Findings on Research, Not Preconceptions.
UX (user experience) designers must question assumptions because assumptions distort understanding. When designers rely on what they only think users want instead of what users actually need, designs will miss the mark. Assumptions often come from personal bias, past experiences, or incomplete data. If designers don’t challenge them, they risk solving the wrong problems or designing for themselves instead of real users.
Questioning assumptions keeps the design process grounded in reality and centered on users’ needs, real-world human needs that need addressing. Even small incorrect assumptions can lead to major usability issues. When you turn assumptions into questions, you can unlock better insights, spark innovation, and build products that actually work in the real world. It’s not about doubting yourself; it’s about designing with clarity and confidence.
Explore additional ways to catapult your creative thinking, with our article Three Ideation Methods to Enhance Your Innovative Thinking.
UX designers often assume users will behave logically, read all the text, or know how to use familiar UI (user interface) elements. They might believe everyone has fast internet, uses the same devices, or wants the same features. These assumptions overlook diversity in user goals, contexts, and abilities.
A classic trap is thinking, “If it makes sense to me, it will make sense to everyone.” In reality, users take shortcuts, skim content, and bring their own experiences. If you assume they’ll read instructions or explore intuitively, you might head down the design track that can lead to confusing interfaces. Good UX design begins when you uncover these blind spots. So, you’ll want to replace your designer assumptions with real user data so you can build inclusive, intuitive experiences that serve a wide range of people.
Get right into the heart of user needs and build a clearer picture of where to direct your focus, away from assumptions.
Start by treating every assumption as a temporary guess. Write them down, then ask yourself: “What do I actually know, and what am I assuming?” Force a clear line between fact and fiction. Replace statements like “Users want X” with “We think users want X because…” and look for evidence. Use user interviews, observation, or analytics to find out if your assumptions hold water.
Invite your team to do assumption-mapping exercises to spot group biases. Even quick hallway tests or card sorting sessions can shake up false beliefs. The key is curiosity: stay open to being wrong. Every challenged assumption gets you closer to a design that solves the real problem, not just the one you imagined.
Discover ways to seize golden opportunities with users, in our article How to Conduct User Interviews.
To challenge assumptions effectively, ask, “What am I assuming here?” Then dig deeper, with: “What evidence supports this?” and “What happens if this isn’t true?” Also try, “Who does this assumption exclude?” or “What user behavior would contradict this?”
These questions force clarity and help uncover gaps in logic or understanding. They spark discussion, too, and encourage diverse thinking. When teams make assumptions visible, they can explore risks, test ideas, and create better solutions. Asking “How do we know?” is powerful; it separates gut instinct from insight. Use these questions during early ideation, wireframing, or usability reviews. They don’t just improve designs; they sharpen your team’s decision-making, too.
Understand user behavior to unlock a treasure trove of insights and help power past assumptions.
Challenge assumptions continuously, at every stage of a UX project. Do it when you’re defining the problem, during research, when sketching solutions, and especially after user testing. Assumptions can sneak in at any time, even from stakeholders or design patterns. Don’t wait until a product launch to find out something doesn’t work; a nasty rude awakening can occur, and users and the marketplace can have long memories regarding your brand.
Treat assumption-checking like a design muscle; use it regularly so it stays strong. Agile teams often revisit assumptions during retrospectives or sprint planning. In user-centered design, the goal is to stay grounded in user reality, not designer opinion. In any case, frequent questioning leads to fewer surprises, better insights, and more confident decisions.
Access helpful insights about agile design and learn how this powerful design approach might work for your team and your brand, and your users.
Yes, user research is vital and certainly one of the best ways to challenge assumptions. It replaces guesswork with evidence. When you observe users interacting with a product or interview them about their needs, you’ll quickly see where your assumptions fall short.
Research can reveal unexpected behaviors, hidden pain points, or new opportunities. For example, you might assume users want a feature, but interviews show they don’t even notice it. Tools like usability testing, surveys, and field studies help surface the truth. Real feedback breaks the illusion of certainty. Use it early and often to shape better questions, better products, and stronger user empathy.
Get a greater grasp of user research and start building a solid foundation on which to help test your assumptions.
To turn an assumption into a testable hypothesis, reframe it using the structure: “We believe [assumption]. If we’re right, then [measurable outcome] will happen when [specific action].” For example, instead of saying “Users want dark mode,” say, “We believe users prefer dark mode. If true, more than 50% will activate it within the first week.”
This neatly scientific approach turns vague beliefs into specific, testable statements. It sets the stage for experiments and user validation. A clear hypothesis keeps teams focused, reduces bias, and speeds up iteration, too. By testing hypotheses early, you validate ideas fast and save time, money, and frustration later.
Discover how to use hypotheses to your benefit, in our article User Research – The Importance of Hypotheses.
Usability testing puts your assumptions on trial. Choose a key assumption, build a prototype, and then observe real users trying to complete tasks. For instance, if you assume a button label is clear, watch if users hesitate or misclick. Their behavior tells the truth. Ask follow-up questions to uncover their reasoning. Usability testing doesn’t just validate what works; it highlights what doesn’t, quickly.
Even five participants can reveal major flaws. Use A/B tests if you’re comparing two versions of a design based on different assumptions. Ultimately, usability testing helps move from “We think” to “We know,” which is where great design begins.
Get right into usability testing and come away with a wealth of insights on how to test assumptions well.
Start by encouraging curiosity over certainty. Praise teammates who question ideas instead of just supporting them. Set a tone that values exploration, not ego. Use structured methods like “assumption storming” or “design critiques” where questioning is expected, not personal.
Create space where even junior designers feel safe asking, “Why did we choose this?” Avoid blame if something fails; instead, celebrate lessons learned. Psychological safety fuels innovation, and teams that feel free to challenge assumptions move faster and build smarter. Leaders should model this behavior by openly admitting their own uncertainties and inviting feedback often.
Delve into design critiques for valuable insights into their function and usefulness in your UX design process.
You know you’ve challenged the right assumptions when your design decisions feel clear, validated, and rooted in real user behavior. What’s the clearest signal? Fewer surprises during testing. If users move smoothly through your design, it means you’ve likely addressed the biggest friction points. Another sign is that the team has shifted from vague debates to focused problem-solving. And if you’ve pivoted or refined your design based on fresh insights, you’re on track.
Yet another important indicator is personas (research-based representations of real users) that accurately reflect your users. Also look for stakeholder alignment; when everyone agrees on user needs, assumptions have likely been brought out in the open and clarified. The right assumptions, once tested, make everything else fall into place.
Peer into the power of personas to appreciate why you definitely want to design with them.
Let’s say your team is designing a mobile banking app. Your starting assumptions might include:
“Users want to see their full balance right after logging in.”
“Two-factor authentication is required every time.”
“Accounts should be listed in order of balance.”
And, when you challenge those assumptions, you might ask:
“What if users prefer a quick-glance summary instead of full balance?”
“What if biometric login is enough security for returning users?”
“What if we sort accounts by frequency of use, not balance?”
These questions open the door to new ideas, like a customizable homepage, gesture-based logins, or smart dashboards that evolve with user behavior.
Explore further insights into how to approach design problems, in our article Product Thinking is Problem Solving.
Oleson, A., Solomon, M., Perdriau, C., & Ko, A. J. (2023). Teaching inclusive design skills with the CIDER assumption elicitation technique. ACM Transactions on Computer-Human Interaction, 30(1), Article 6.
This paper introduces the CIDER (Critique, Imagine, Design, Expand, Repeat) technique aimed at making designers explicitly surface and challenge assumptions about users. The study shows how 40 undergraduate interaction-design students used CIDER over an 11-week course to identify design biases rooted in assumptions (e.g., user has certain abilities, access, background). It demonstrates that assumption-elicitation can improve awareness of exclusion and lead to more inclusive redesigns. Its importance lies in operationalizing “assumption challenging” as a teachable method, bridging the gap between abstract calls for seldom-questioned assumptions and concrete pedagogical/ design practice.
Gothelf, J., & Seiden, J. (2021). Lean UX: Designing Great Products with Agile Teams (3rd ed.). O’Reilly Media.
This book explicitly emphasizes surfacing, articulating and testing assumptions in the UX/design process. The authors introduce the “Lean UX Canvas” as a tool to capture hypotheses and assumptions about users, business outcomes and solutions, and then rapidly validate them through experiments.
The agile/lean orientation makes it particularly applicable to cross‑functional teams in digital product design. By shifting the focus from deliverables (wireframes, specs) to continuous learning about what really matters, the book helps designers challenge their implicit beliefs about users and move toward evidence‑based decisions.
Knapp, J., Zeratsky, J., & Kowitz, B. (2016). Sprint: How to Solve Big Problems and Test New Ideas in Just Five Days. Simon & Schuster.
While this book is not exclusively UX‑design theory, it offers a clear, time‑boxed methodology for rapidly challenging assumptions: take a big idea, build a prototype over five days, and test it with real humans. In doing so, you learn whether your core assumptions hold or need to be discarded. The method originated at Google Ventures and is applied by teams to expose hidden assumptions about user behavior, value propositions and product–market fit. The emphasis on validating assumptions early means this book is highly relevant when you’re designing with uncertainty and want to avoid building based purely on untested beliefs.
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